In recent years, there have been increasing opportunities of using adhesive sheets for labels as labels such as labels for indicating prices, labels for indicating products (barcodes), labels for indicating qualities, labels for indicating measures, labels for advertisements (stickers), etc. There are many recording methods for performing recording over the labels, such as an inkjet recording method and a thermal recording method.
Hitherto, typical adhesive sheets having a configuration obtained by laminating an adhesive layer and a release paper over a surface of a label opposite to a surface over which information is recorded have been widely used because these sheets are easy to stick only by peeling the release paper and applying a pressure.
However, while adhesive sheets having the typical configuration are used by peeling the release paper, the peeled release paper have hardly been collected and recycled but have most often been disposed of.
Linerless labels, which are obtained by forming a release layer having releasability over a surface of the labels, can be used in a wound state without a release paper. This realizes roll-shaped linerless labels. Linerless labels include no release paper to be disposed of and can reduce environmental impacts.
Linerless labels are a continuous body. Therefore, linerless labels can be used as labels by being cut with a cutting apparatus having a cutter blade.
When linerless labels are cut with a cutting apparatus, the adhesive over the back surface of the labels adheres to and accumulates over the cutter blade and reduces the cuttability of the cutter blade. This gives rise to inconvenience of removing the adhesive that has adhered to the cutter blade, etc.
To overcome this inconvenience, there are proposed techniques for modifying not the linerless labels but a label printer apparatus to suppress adhesion of the adhesive to the cutter blade (see, e.g., PTLs 1 and 2). However, these techniques are for developing apparatuses and hence limit the printers that can be used.
There are also proposed techniques for applying the adhesive over the linerless labels in a pattern to form adhesive portions and non-adhesive portions in order for the non-adhesive portions to be cut to prevent adhesion of the adhesive (see, e.g., PTLs 3, 4, 5, and 6). However, these techniques use a special applying method and hence have a low productivity.
There is also proposed a technique for providing an applied layer containing a release agent such as a silicone-based polymeric compound over a to-be-cut portion of a base such that every time a linerless label is cut by the cutter blade, the edge of the blade is coated with the release agent contained in the applied layer at the eye mark for the to-be-cut portion to prevent adhesion of the adhesive (see, e.g., PTL 7). However, this technique needs to provide the eye-mark applied layer selectively at the to-be-cut portions beforehand. Therefore, when labels with a plurality of different printing lengths are to be issued from the same continuous label, there occurs inconvenience that an applied layer is not provided at a portion to be cut, etc.
As an example in which no such special fabrication as described above is applied to a to-be-cut portion, there is proposed a technique for a linerless label for thermal recording, wherein an undercoat layer, a thermosensitive color-developing layer, a barrier layer, and a release layer are laminated sequentially over one surface of a support of the linerless label and an adhesive layer is provided over another surface of the support (see, e.g., PTL 8). However, this technique applies the adhesive over a surface of the release layer, dries the adhesive, and winds up the layers in a roll shape to stick the release layer to the back surface of the thermal recording medium. Therefore, the adhesive remains over the release layer, leading to a problem that in cutting with a printer, cuttability of the printer sharply degrades and print image fading occurs frequently.
It is possible to reduce the amount of the adhesive to be applied over the linerless label to reduce adhesion of the adhesive to the cutter blade. However, this method reduces the adhesive force and makes the function as the label problematic.
As described above, when a linerless label is cut with a cutting apparatus, the adhesive over the back surface of the label adheres to and accumulates over the cutter blade. This causes label jamming or reduces cuttability of the cutter. When the linerless label is a linerless label for thermal recording and the cutting apparatus is a thermal recording apparatus including a feedback function, print image fading occurs if the adhesive having accumulated over the cutter blade moves and accumulates over a thermal head.